Release 2.1.2

Fixes for:
- Support for Mantis, the OpenTok media server for WebRTC.
- Bugs related to backgrounding the application.
- Added native support for armv7s architecture
- Fixed a bug that causes inconsistent UI when manipulating
  media track functions (eg. publishVideo, subscribeToAudio, etc.)
Merge pull request #9 from wobbals/release/2.1.2

Release 2.1.2